1. Field of the Invention
This invention relates generally to industrial furnaces and, more particularly to, an apparatus and a method for using a roof filler module to access and replace a failed heat source while the industrial furnace remains in operation.
2. Discussion of Related Art
Industrial furnaces are used in many applications such as, but not limited to, producing glass on a tin bath, heat treating, smelting and/or refining metals, calcining coke, incinerating waste and the like. Industrial furnaces are often constructed of refractory materials, such as taught by U.S. Pat. Nos. 6,427,610 and 4,960,058, the entire teachings of which are incorporated by reference into this specification. The use of hanger bricks and filler bricks for roof construction is effective in industrial furnaces, particularly for making glass.
A tin bath system in an industrial furnace is currently used to manufacture flat glass. The glass is formed in a flat sheet by dispersing molten glass across a bath of molten tin alloy and because the glass has the lower specific gravity, it floats on the molten metal. The interface of the glass and molten tin alloy is nearly perfectly flat, forming one side of the sheet. The sheet is heated by the molten metal on one side and by a heat source on the other side of the sheet, in order to allow for a process of stretching and relaxing the sheet, which results in a substantially flat top surface.
During operation of the tin bath system, a heat source sometimes fails. Over time, failure of one or more heat sources may jeopardize the glass-forming process, and in extreme cases, may require shutting the process down to repair or replace the failed heat sources. The resulting loss of production time can be very costly to a manufacturer. A filler element that allows replacement of a failed heat source during tin bath operation is highly desirable, particularly where only a small area of the industrial furnace is exposed to the surrounding environment.